Slime, gunge (3)
I believe the answer is:
goo
I believe this is a double definition.
'slime' is the first definition.
(synonyms)
'gunge' is the second definition.
(I've seen this before)
(Other definitions for goo that I've seen before include "Sticky or slimy substance" , "syrup" , "Anything sticky" , "Viscous matter" , "Sticky matter" .)